The application of adsorptive potentiometric stripping analysis (AdPSA) to the oxidative detection of dopamine (DA) on Nafion(R)-coated nontronite-modified electrode (NCNME) has been demonstrated. Combination of a Nafion(R) coating to discriminate DA from interference with nontronite clay to improve DA accumulation works excellently in DA detection. Anodic pretreatment of the NCNME increases the sensitivity through the positive interaction between the preanodized clay and DA. Variables influencing the AdPSA response are thoroughly explored and optimized. The preconcentration time required in AdPSA is much shorter than in other techniques. Electrocatalysis between the oxidative product of DA and ascorbic acid further increases the AdPSA signal. (C) 1998 Elsevier Science B.V. All rights reserved.